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  • Rare earth elements  (2)
  • CO2 fluxes  (1)
  • 1
    Publication Date: 2022-05-26
    Description: Author Posting. © American Geophysical Union, 2012. This article is posted here by permission of American Geophysical Union for personal use, not for redistribution. The definitive version was published in Geophysical Research Letters 39 (2012): L07606, doi:10.1029/2012GL051574.
    Description: The carbon system of the western Arctic Ocean is undergoing a rapid transition as sea ice extent and thickness decline. These processes are dynamically forcing the region, with unknown consequences for CO2 fluxes and carbonate mineral saturation states, particularly in the coastal regions where sensitive ecosystems are already under threat from multiple stressors. In October 2011, persistent wind-driven upwelling occurred in open water along the continental shelf of the Beaufort Sea in the western Arctic Ocean. During this time, cold (〈−1.2°C), salty (〉32.4) halocline water—supersaturated with respect to atmospheric CO2 (pCO2 〉 550 μatm) and undersaturated in aragonite (Ωaragonite 〈 1.0) was transported onto the Beaufort shelf. A single 10-day event led to the outgassing of 0.18–0.54 Tg-C and caused aragonite undersaturations throughout the water column over the shelf. If we assume a conservative estimate of four such upwelling events each year, then the annual flux to the atmosphere would be 0.72–2.16 Tg-C, which is approximately the total annual sink of CO2 in the Beaufort Sea from primary production. Although a natural process, these upwelling events have likely been exacerbated in recent years by declining sea ice cover and changing atmospheric conditions in the region, and could have significant impacts on regional carbon budgets. As sea ice retreat continues and storms increase in frequency and intensity, further outgassing events and the expansion of waters that are undersaturated in carbonate minerals over the shelf are probable.
    Description: Funding for this work was provided by the National Science Foundation (ARC1041102 – JTM, OPP0856244-RSP, and ARC1040694- LWJ), the National Oceanic and Atmospheric Administration (CIFAR11021- RHB) and the West Coast & Polar Regions Undersea Research Center (POFP00983 – CLM and JM).
    Description: 2012-10-11
    Keywords: Arctic Ocean ; CO2 fluxes ; Ocean acidification ; Upwelling
    Repository Name: Woods Hole Open Access Server
    Type: Article
    Format: text/plain
    Format: image/tiff
    Format: application/msword
    Format: application/pdf
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  • 2
    Electronic Resource
    Electronic Resource
    Springer
    Journal of solution chemistry 22 (1993), S. 751-766 
    ISSN: 1572-8927
    Keywords: Rare earth elements ; fluoride complexation ; stability constant ; solvent exchange ; tributyl phosphate ; sodium perchlorate
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology
    Notes: Abstract Rare earth fluoride stability constants for Ce, Eu, Gd, Tb and Yb at 25°C have been determined by examining the influence of fluoride ions on the distribution of rare earths between tributyl phosphate (TBP) and 0.68M NaClO4. Our results indicate that rare earth mono and difluoro complexation constants show a steady increase as a function of atomic number from La to Tb but remain relatively constant after Dy. This behavior is similar to that which has been observed for dicarboxylic acids. Stepwise stability constant ratios, K2/K1, obtained in our work (where K1=[MF2+][M3+]−1[F−]−1 and K2=[MF 2 + ]−1[MF2+]−1[F−]−1) indicated that, for all rare earths, K2/K1=0.09±0.03.
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  • 3
    Electronic Resource
    Electronic Resource
    Springer
    Journal of solution chemistry 29 (2000), S. 1089-1099 
    ISSN: 1572-8927
    Keywords: Rare earth elements ; fluoride complexation ; stability constants ; sodium perchlorate ; ionic strength ; lanthanide ; yttrium
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology
    Notes: Abstract Formation constants for the complexation of yttrium and rare earth elements(YREE) by fluoride ions have been measured at 25°C. The ionic strength (μ)dependence of YREE formation constants in perchlorate solution for ionicstrengths between 0 and 6 molar can be expressed aslogFβ1 (M, μ) =logFβ1 o (M) −3.066 μ0.5/(1 + 1.769 μ0.5)+ 0.1645 μwhere logFβ1 o(M) represents MF2+formation constants at zero ionic strength.The logFβ1 o(M) results obtained inthis work are: Y(4.46), La(3.62), Ce(3.86),Pr(3.84), Nd(3.82), Sm(4.15), Eu(4.27), Gd(4.24), Tb(4.37), Dy(4.39), Ho(4.28),Er(4.27), Tm(4.29), Yb(4.39), and Lu(4.25). The relative magnitudes of YREEformation constants are independent of ionic strength. The pattern oflogFβ1(M,μ),formation constants obtained in this work [relative magnitudes oflogFβ1 o (M)],exhibits a shallow minimum between Dy and Yb. In contrast to the smoothpattern of stability constants expected if fluoride were to interact with bare ions(with monotonically decreasing crystal radii between La and Lu), theinteractionof F− with YREEs, which have extensive hydration spheres[M(H2O)8–9 3+] resultsin a relatively complex pattern of lanthanide stability constants. The fluoridecomplexation behavior of yttrium differs distinctly from the behavior of any rareearth. Although the crystal radius of Y3;pl is approximately equalto that of Ho3+,differences in the covalence/ionicity of Y3+ relative to therare earths leads to aYF2+ stability constant that exceeds that of any rare earthelement (REE).
    Type of Medium: Electronic Resource
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